Sorting game
This game is conceptually similar to Mastermind in this respect: one player sets up a configuration, and the second player tries to guess it by asking as few questions as possible.
How the game is played.
The first player has a sheet of paper (hidden from the second player) with five columns labeled by the letters A, B, C, D, and E, and a Score column.
The first player creates a problem to be solved by putting the numbers 0, 1, 2, 3, and 4, in some order (but without repetitions) in the columns A to E.
Example.
| A | B | C | D | E | Score: | |
| 1 | 0 | 4 | 3 | 2 |
The second player may ask only questions of the form:
"Which is bigger, X or Y?"
where X and Y are the letters A to E.
The first player must answer truthfully either "X" or "Y", and put a mark, |, in the score column after each question.
When the second player thinks that he/she knows the answer, he/she gives the values of A, B, C, D, and E.
The second player is allowed to keep track of the questions and answers by writing them down, and must figure out the best way to ask the next one.
So the game should be played rather slowly.
Scoring.
If the second player guesses wrong, he/she gets a score of -1 as a penalty.
If the guess is correct, the second player gets
10 - (number of questions he/she asked).
But if this value is less than 0, the second player just gets 0 and is not penalized for additional questions.
Changing roles.
After several games (for example 5), the players change roles, and at the end they compare their scores to declare the winner. One can also hold tournaments among groups of players, or play in teams.
Example of a game:
Position at the start:
| A | B | C | D | E | Score: | |
| 1 | 0 | 4 | 3 | 2 |
|
Questions: |
Answer: |
Score: |
|
|
Which is bigger, |
|||
|
A or B? |
A |
| |
|
|
A or C? |
C |
|| |
|
|
C or D? |
C |
||| |
|
|
C or E? |
C |
|||| |
|
|
E or D? |
D |
||||| |
|
|
A or D? |
D |
|||||| |
|
|
B or E? |
E |
||||||| |
|
|
A or E? |
E |
|||||||| |
|
I know A = 1, B = 0, C = 4, D = 3, and E = 2.
Position at the end:
| A | B | C | D | E | Score: | |
| 1 | 0 | 4 | 3 | 2 | ||||||| 2 |
The answer was correct after 8 questions, so the second player scored 10 - 8 = 2 points.
Remarks.
- A good player never needs more than 8 questions, and a master player never needs more than 7 questions!
- To become a good player you have to design a strategy which utilizes efficiently the information that you gather.
- It is helpful for the second player to have 5 tokens marked with the letters A through E, to keep track of the information that is gathered.